Summary

Return to preinjury levels of performance did not affect graft remodeling in two years after anterior cruciate ligament reconstruction using bone‐patellar tendon‐bone autograft.

Abstract

<Background>
The graft transplanted in the intra-articular environment in anterior cruciate ligament reconstruction (ACLR) undergoes several remodeling processes post-operatively. Although a substantial time, which varies from 6 to 48 months, is required to achieve the graft remodeling, ACL patients aim to return to preinjury levels of performance (RTP) around 1 year after ACLR. Therefore, a longer remodeling maturation time of ACL graft could present a challenge after RTP.
This study aims to assess whether RTP affects ACL graft remodeling after ACLR using BPTB autograft with a serial 3-T MRI.
<Methods>
This retrospective study consisted of 111 patients who underwent primary ACLR using BPTB autograft, CT scans at 1 week, and serial MRI examinations at 6, 12, and 24 months post-operatively. Patients were divided into two groups depending on whether the patients were able to RTP (group A) or not (group B).
The signal intensity on MRI was measured in 3 regions (proximal, middle, and distal sites) of the intra-articular ACL graft.
The average signal/noise quotient (SNQ) of the three regions was calculated and used as the SNQ value of the ACL graft on MRI. The amount of changes in SNQ value (1) from 6 to 12 months after ACLR (ΔSNQ [6-12]) and (2) from 12 to 24 months (ΔSNQ [12-24]) were calculated.
Femoral graft bending angle (GBA) on CT and medial and lateral posterior tibial slope (PTS) on MRIs were measured.
To investigate the association of age, gender, body mass index (BMI), cartilage injury, post-operative Tegner score, and RTP with ΔSNQs, a fixed‐effect multivariate logistic regression analysis was conducted.
<Results>
There were 83 patients (38 males and 45 females) in group A and 28 (10 males and 18 females) in group B, respectively. The average age in group A (23.3 y.o.) was significantly older than in group B (18.1 y.o.) whereas there were no significant differences in gender, BMI, time to surgery, GBA, and PTS between the two groups. The incidence of cartilage injury in group A (83.3%) was significantly higher than in group B (0%) whereas there was no difference in the incidence of meniscal injury between the two groups. The average time of RTP was 10.4 months. Additionally, the average post-operative Tegner score in group A (7.9) was significantly higher than in group B (6.2).
The SNQ value at 24 months in group A (1.47) was significantly higher than in group B (1.29) while there were no differences at 6 (1.35 vs 0.80) and 12 months (1.08 vs 1.39). In addition, ΔSNQ (12-24) in group A (0.38) was significantly higher than in group B (-0.10) while ΔSNQ (6-12) was -0.27 in group A and 0.59 in group B, respectively.
The multivariate logistic regression analysis showed that age, gender, BMI, cartilage injury, post-operative Tegner score, and RTP were not associated with ΔSNQs.
<Conclusion>
RTP did not affect graft remodeling in 2 years after ACLR using BPTB autograft while 74.8% of patients were able to RTP around 10 months post-operatively.